.... Verizon 11:17 AM 18% 4. The Federal Trade Commission (FTC) has, for several years, studied the accuracy of price scanners used in many retail stores. Grocery stores were found, in general, to have a smaller incidence of scanner errors than non- grocery retail stores. The manager of a Richmond retailer (non-grocery) wishes to investigate scanner errors at his store. A random sample of 101 scanner transactions from last week's purchases is obtained, and the average transaction error is + $4.32 with a standard deviation of $1.52. In other words, the customers making these 101 transactions were over charged, on average, by amount $4.32. Use the sample data to calculate and interpret a 90%confidence interval for the mean transaction error in the population of scanner transactions that occurred at this store last week. (4+2=6 pts) b. Determine the margin of error for the interval estimate in a, and explain what it represents about scanner errors. (2 pts)